Localization of the aap gene product. Western immunoblot analysis was performed on 042 grown in L-broth and subjected to addition of 0.1% Triton X-100 detergent, incubation at 60°C for 20 minutes, or vigorous vortexing for 10 minutes. Cultures were grown to late log phase, and bacteria were pelleted by centrifugation. Pellets (P) were prepared by boiling whole pellet in SDS-PAGE buffer and separating 10% of the sample derived from a 1.0-ml culture. Supernatant (S) was prepared by TCA precipitation. Western immunoblots were performed by standard methods using highly specific polyclonal antiserum to Aap protein. Aap migrates at the predicted 10-kDa size.